I have the Aerobat and it was my first airplane. I would disagree with the Avistar being one that takes a long time to outgrow because if I remember right, it has more dihedral than the aerobat, and the Aerobat has a few other neat advantages over the Avistar as well....

With the Aerobat, you can set up flaperons if you so choose, you can also convert it later to a taildragger without much trouble (the blocks to move the mains forward are already installed), and there is less dihedral.

With less dihedral, you'll be able to pull more areobatics off without as much slop. Granted, they are still sloppy because the plane tends to roll a little with rudder input and the rolls are less than axial, but its still more plane for your buck. Thow it on high rates and the roll improves significantly.

Just my few pesos.